Obstructive sleep apnea syndrome (OSAS) is the most common indication for tonsillectomy and adenoidectomy in young children. According to previous studies, as much as 8 to 20% of patients will develop post operative respiratory complications requiring medical intervention. The pre-operative risk factors that could predict respiratory complications retrospectively analyzed were young age, obesity and high preoperative apnea-hypopnea index. Despite the removal of obstructing lymphoid tissue, upper airway obstruction occurs on the first postoperative night in children with OSA. There is a debate regarding the post-operative duration and monitoring needed in children with OSA.